I designed a custom insert for these $6 Harbor Freight cases to hold tools I needed for my smaller tool cart for work. I know my specific layout may not be useful to others, which is why I have also included the blank that fits snug into the case that you can make your own layout to fit what you want to put inside the case. I have added a couple dividers that can be duplicated and stretched as needed just make sure you keep the height the same as the blank insert height. Simply place the dividers how you want them and slice which will merge them together as a single piece. I do not know if this will fit the A1 mini but I am assuming it is too large.

Link to the storage case this fits.

https://www.harborfreight.com/15-bin-small-portable-parts-storage-case-64811.html